package com.tianji.learning.service.impl;

import com.baomidou.mybatisplus.core.metadata.TableFieldInfo;
import com.baomidou.mybatisplus.core.toolkit.Wrappers;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.tianji.api.cache.CategoryCache;
import com.tianji.api.client.course.CatalogueClient;
import com.tianji.api.client.course.CourseClient;
import com.tianji.api.client.search.SearchClient;
import com.tianji.api.client.user.UserClient;
import com.tianji.api.dto.course.CataSimpleInfoDTO;
import com.tianji.api.dto.course.CourseSimpleInfoDTO;
import com.tianji.api.dto.user.UserDTO;
import com.tianji.common.domain.dto.PageDTO;
import com.tianji.common.exceptions.BadRequestException;
import com.tianji.common.exceptions.BizIllegalException;
import com.tianji.common.utils.BeanUtils;
import com.tianji.common.utils.CollUtils;
import com.tianji.common.utils.StringUtils;
import com.tianji.common.utils.UserContext;
import com.tianji.learning.domain.dto.QuestionFormDTO;
import com.tianji.learning.domain.po.InteractionQuestion;
import com.tianji.learning.domain.po.InteractionReply;
import com.tianji.learning.domain.query.QuestionAdminPageQuery;
import com.tianji.learning.domain.query.QuestionPageQuery;
import com.tianji.learning.domain.vo.QuestionAdminVO;
import com.tianji.learning.domain.vo.QuestionVO;
import com.tianji.learning.mapper.InteractionQuestionMapper;
import com.tianji.learning.service.IInteractionQuestionService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.tianji.learning.service.IInteractionReplyService;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Service;

import java.util.*;
import java.util.function.Predicate;
import java.util.stream.Collectors;

/**
 * <p>
 * 互动提问的问题表 服务实现类
 * </p>
 *
 * @author root
 * @since 2023-10-26
 */
@Service
@Slf4j
@RequiredArgsConstructor
public class InteractionQuestionServiceImpl extends ServiceImpl<InteractionQuestionMapper, InteractionQuestion> implements IInteractionQuestionService {

    private final IInteractionReplyService replyService;
    private final UserClient userClient;
    private final SearchClient searchClient;
    private final CourseClient courseClient;
    private final CatalogueClient catalogueClient;
    private final CategoryCache categoryCache;

    @Override
    public void saveQuestion(QuestionFormDTO dto) {
        // 1. 获取当前登录用户
        Long userId = UserContext.getUser();
        // 2. dto 转 po
        InteractionQuestion question = BeanUtils.copyBean(dto,InteractionQuestion.class);
        question.setUserId(userId);

        // 3. 保存
        this.save(question);
    }

    @Override
    public void updateQuestion(Long id, QuestionFormDTO dto) {
        // 1. 校验
        if(StringUtils.isBlank(dto.getTitle()) || StringUtils.isBlank(dto.getDescription()) || dto.getAnonymity() == null){
            throw new BadRequestException("非法参数");
        }
        // 校验 id
        InteractionQuestion question = this.getById(id);
        if (question == null){
            throw new BadRequestException("非法参数");
        }
        // 只能修改自己的问题
        Long userId = UserContext.getUser();
        if(!userId.equals(question.getUserId())){
            throw new BadRequestException("只能修改自己的问题");
        }
        // 2. dto 转 po
        question.setTitle(dto.getTitle());
        question.setAnonymity(dto.getAnonymity());
        question.setDescription(dto.getDescription());
        // 3. 修改
        this.updateById(question);

    }

    @Override
    public PageDTO<QuestionVO> queryQuestionPage(QuestionPageQuery query) {
        // 1. 检验参数 courseId
        if(query.getCourseId() == null){
            throw new BadRequestException("课程id 不能为空");
        }
        // 2. 获取登录用户
        Long userId = UserContext.getUser();
        // 3. 分页查询互动问题 interaction_question 条件: course  当onlyMine=true还要有userId  小节id不为空  hidden=false  分页  按提问时间倒叙 去除: description 因为较大且前端不需要
        Page<InteractionQuestion> page = this.lambdaQuery()
//                .select(InteractionQuestion.class, new Predicate<>() {
//                    @Override
//                    public boolean test(TableFieldInfo tableFieldInfo) {
//                        //tableFieldInfo.getProperty() 获取 InteractionQuestion 实体类的属性
//                        return !tableFieldInfo.getProperty().equals("description");// 指定不查的字段
//                    }
//                })
                .select(InteractionQuestion.class,tableFieldInfo -> !tableFieldInfo.getProperty().equals("description"))// 上面代码简写
                .eq(InteractionQuestion::getCourseId, query.getCourseId())
                .eq(query.getOnlyMine(), InteractionQuestion::getUserId, userId)
                .eq(query.getSectionId() != null, InteractionQuestion::getSectionId, query.getSectionId())
                .eq(InteractionQuestion::getHidden, false)
                .page(query.toMpPageDefaultSortByCreateTimeDesc());
        List<InteractionQuestion> records = page.getRecords();
        if (CollUtils.isEmpty(records)){
            return PageDTO.empty(page);
        }
        Set<Long> lastestAnswerIds = new HashSet<>();// 互动问题的最新回答id集合
        Set<Long> userIds = new HashSet<>();//互动问题的用户id 集合
        for (InteractionQuestion record: records){
            if(!record.getAnonymity()){//判断匿名
                userIds.add(record.getUserId());
            }

            if(record.getLatestAnswerId() != null){
                lastestAnswerIds.add(record.getLatestAnswerId());
            }
        }
//        stream 的写法
//        Set<Long> lastestAnswerIds = records.stream()
//                .filter(c -> c.getLatestAnswerId()!=null)//对原数据进行过滤
//                .map(InteractionQuestion::getLatestAnswerId)//指定查询某个字段
//                .collect(Collectors.toSet());
        // 4. 根据最新回答id 批量查询回答信息  Interaction_reply  条件：id集合
        Map<Long,InteractionReply> replyMap = new HashMap<>();
        if(CollUtils.isNotEmpty(lastestAnswerIds)){
            // List<InteractionReply> replyList = replyService.listByIds(lastestAnswerIds);
            List<InteractionReply> replyList = replyService.list(Wrappers.<InteractionReply>lambdaQuery()
                    .in(InteractionReply::getId, lastestAnswerIds)
                    .eq(InteractionReply::getHidden, false));

            for (InteractionReply reply:replyList){
                if(!reply.getAnonymity()){ //判断匿名
                    userIds.add(reply.getUserId()); //将最新回答的用户id 存入userIds
                }

                replyMap.put(reply.getId(),reply);
            }
        }
        // 5. 远程调用用户服务 获取用户信息
        List<UserDTO> userDTOS = userClient.queryUserByIds(userIds);
        Map<Long, UserDTO> userDTOMap = userDTOS.stream().collect(Collectors.toMap(UserDTO::getId, c -> c));
        // 6. 封装 vo 返回
        List<QuestionVO> voList = new ArrayList<>();
        for(InteractionQuestion record:records){
            QuestionVO vo = BeanUtils.copyBean(record, QuestionVO.class);
                if(!vo.getAnonymity()){
                    UserDTO userDTO = userDTOMap.get(record.getUserId());
                    if(userDTO != null){
                        vo.setUserIcon(userDTO.getIcon());
                        vo.setUserName(userDTO.getName());
                    }

            }
            InteractionReply reply = replyMap.get(record.getLatestAnswerId());
            if(reply != null){ 
                if(!reply.getAnonymity()){
                    UserDTO userDTO = userDTOMap.get(reply.getUserId());
                    if(userDTO != null){
                        vo.setLatestReplyUser(userDTO.getName());//最新回答者的昵称
                    }

                }
                vo.setLatestReplyContent(reply.getContent());//最新回答的内容
            }

            voList.add(vo);
        }

        return PageDTO.of(page,voList);
    }

    @Override
    public QuestionVO queryQuestionById(Long id) {
        // 1. 校验
        if(id==null){
            throw new BadRequestException("非法参数");
        }
        // 2. 查询互动问题表，按主键查询
        InteractionQuestion question = this.getById(id);
        if(question == null){
            throw new BadRequestException("用户不存在");
        }
        
        // 3. 问题被隐藏，返回 null
        if(question.getHidden()){
            return null;
        }
        // 4. 封装 vo 返回
        QuestionVO questionVo = BeanUtils.copyBean(question, QuestionVO.class);
        // 5. 匿名，不查询昵称和头像
        if(!question.getAnonymity()){
            UserDTO userDTO = userClient.queryUserById(question.getUserId());
            if(userDTO != null){
                questionVo.setUserName(userDTO.getName());
                questionVo.setUserIcon(userDTO.getIcon());
            }
        }
        return questionVo;
    }

    @Override
    public PageDTO<QuestionAdminVO> queryQuestionAdminVOPage(QuestionAdminPageQuery query) {
        // 0. 如果用户传了课程的名称参数 则从 ES
        String courseName = query.getCourseName();
        List<Long> cids = null;
        if(StringUtils.isNotBlank(courseName)){
            cids = searchClient.queryCoursesIdByName(courseName);//通过feign远程调用搜索服务，从ES中搜索该关键字对应的课程id
            if (CollUtils.isEmpty(cids)){
                return PageDTO.empty(0L,0L);
            }
        }

        // 1. 查询互动问题表  条件: 前端传条件了就添加条件   分页   排序按提问时间排序
        Page<InteractionQuestion> page = this.lambdaQuery()
                .in(CollUtils.isNotEmpty(cids),InteractionQuestion::getCourseId, cids)
                .eq(query.getStatus() != null, InteractionQuestion::getStatus, query.getStatus())
                .between(query.getBeginTime() != null && query.getEndTime() != null,
                        InteractionQuestion::getCreateTime, query.getBeginTime(), query.getEndTime())
                .page(query.toMpPageDefaultSortByCreateTimeDesc());
        List<InteractionQuestion> records = page.getRecords();
        if (CollUtils.isEmpty(records)){
            return PageDTO.empty(0L,0L);
        }

        Set<Long> uids = new HashSet<>(); //用户 id 集合
        Set<Long> courseIds = new HashSet<>();//课程id集合
        Set<Long> chapterAndSectionIds = new HashSet<>();//章和节的id集合
        for(InteractionQuestion record:records){
            uids.add(record.getUserId());
            courseIds.add(record.getCourseId());
            chapterAndSectionIds.add(record.getChapterId());//章
            chapterAndSectionIds.add(record.getSectionId());//节
        }
        // 2. 远程调用用户服务，获取用户信息
        List<UserDTO> userDTOS = userClient.queryUserByIds(uids);
        if(CollUtils.isEmpty(userDTOS)){
            throw new BizIllegalException("用户不存在");
        }
        Map<Long, UserDTO> userDTOMap = userDTOS.stream().collect(Collectors.toMap(UserDTO::getId, c -> c));
        // 3. 远程调用课程服务，获取课程信息
        List<CourseSimpleInfoDTO> cinfos = courseClient.getSimpleInfoList(courseIds);
        if (CollUtils.isEmpty(cinfos)){
            throw new BizIllegalException("课程不存在");
        }
        Map<Long, CourseSimpleInfoDTO> cinfoMap = cinfos.stream().collect(Collectors.toMap(CourseSimpleInfoDTO::getId, c -> c));

        // 4. 远程调用课程服务，获取章节信息
        List<CataSimpleInfoDTO> cataSimpleInfoDTOS = catalogueClient.batchQueryCatalogue(chapterAndSectionIds);
        if(CollUtils.isEmpty(cataSimpleInfoDTOS)){
            throw new BizIllegalException("章节信息不存在");
        }
        Map<Long, String> cataInfoDTO = cataSimpleInfoDTOS.stream().collect(Collectors.toMap(CataSimpleInfoDTO::getId, c -> c.getName()));

        // 6. 封装 vo 返回
        ArrayList<QuestionAdminVO> voList = new ArrayList<>();
        for (InteractionQuestion record : records){
            QuestionAdminVO adminVO = BeanUtils.copyBean(record, QuestionAdminVO.class);

            UserDTO userDTO = userDTOMap.get(record.getUserId());
            if(userDTO != null){
                adminVO.setUserName(userDTO.getName());
            }

            CourseSimpleInfoDTO cinfoDTO = cinfoMap.get(record.getCourseId());
            if(cinfoDTO != null){
                adminVO.setCourseName(cinfoDTO.getName());
                List<Long> categoryIds = cinfoDTO.getCategoryIds();//一二三级分类id集合
                // 5. 获取分类信息
                String categoryNames = categoryCache.getCategoryNames(categoryIds);
                adminVO.setCategoryName(categoryNames);//三级分类名称，拼接字段
            }
            adminVO.setChapterName(cataInfoDTO.get(record.getChapterId()));//章名称
            adminVO.setSectionName(cataInfoDTO.get(record.getSectionId()));//节名称

            voList.add(adminVO);
        }
        return PageDTO.of(page,voList);
    }
}
